Fluid resistant coating composition

ABSTRACT

A fire-retardant, fluid-resistant coating composition having enhanced bonding strength and increased aesthetic appeal. The composition, comprising from 3-4 parts of a liquid acrylic emulsion, from 1-2 parts of a liquid latex polymer suspension, from 1-3 parts of an adhesive material and from 1-2 parts of a gypsum-based powder, may be sprayed, brushed or rolled onto a variety of substrates. A coated product may also be produced by applying the coating composition to a substrate comprising a reinforcing material such as glass fibres so as to form sheets or laminates which may be rolled for transportation and storage with minimal danger of cracking, chipping or peeling. The composition may also be utilized to provide an adhesive bond by applying it to a surface of a first substrate and then contacting the coated surface with a second substrate while the composition is still viscous.

This is a division of application Ser. No. 40,012, filed Apr. 17, 1987,now U.S. Pat. No. 4,845,144.

FIELD OF THE INVENTION

The invention relates to a coating composition and products producedtherewith for providing improved weatherproofing and structuralstrength, coupled with an attractive aesthetic appearance and a tightlyadherent bond to a substrate so that the coating is capable of resistingchipping and cracking.

BACKGROUND OF THE INVENTION

A coating may be defined as a layer of a substance which is used toprotect and/or decorate a surface. It must adhere to a substrate, incontrast to a covering, which may simply surround or lie over thesurface of such a substrate without bonding thereto. Coatings areprimarily available as liquid or fusible compositions wherein the liquidportions are usually aqueous or organic solutions. Coating are meant tobe applied to the surface of a substrate to be treated. The liquidportion enables the coating to flow smoothly over the surface of thesubstrate, chiefly due to forces of surface tension, before evaporatingor reacting with the other coating components to form a solid, tightlyadherent composition thereon.

At the time of application, coatings generally include an organicpolymeric binder, one or more pigments, a volatile thinner or solventand various additional additives. Each ingredient, in itself, may be acomplicated mixture, depending upon the end use of the coating.

The binder is ordinarily a film-forming organic polymer, such ascellulose nitrate, an alkyd resin, or a mixture of such polymers, havingglassy, plastic, or rubbery properties in the dried state. Binders aregrouped into certain overlapping classes, such as acrylic, vinyl, alkyd,polyester, etc. The structure of the binder molecules and the forcesoperating between the molecules determines the properties of thesebinders. The polymeric binder thus adheres to the substrate and alsobinds the pigment particles, if present, into a coherent film.

The pigments are inorganic or organic powders of varying hiding powerand color. They are practically insoluble in the binder and confercolor, opacity, and a variety of mechanical and physical properties tothe film.

The volatile thinner or solvent, which evaporates after the coating isapplied, is used to reduce the consistency of the coating so that it maybe brushed, sprayed, calendered, dipped, electrocoated, or otherwiseapplied to the surface of a substrate. Volatile thinners include avariety of organic liquids, such as esters, alcohols, ketones, naphthas,or paraffin hydrocarbons, depending upon the required solubilitycharacteristics of the particular binder. The thinner may be water, as,for example, in emulsion coatings, or an organic nonsolvent, as inorganosols.

Small percentages of other materials may also be included within theabove described coating compositions as additives, such as metallicdriers for coatings that dry by oxidation, agents to stabilize pigmentdispersions and agents to reduce or eliminate foaming of the compositionduring mixing.

One common type of coating composition is paint, which is made up ofpigments blended intimately with a binder. The film-forming materials,i.e., mainly the pigment and binder, are together called thenonvolatiles, or solids. A binder, with or without a thinner, butwithout pigment, can be generally referred to as a varnish, or sometimesas a "clear lacquer."

Some coatings for specialized applications are applied as monomers andthen polymerized in situ. However, most coatings applied as liquids formdry films in other ways. Air-drying coatings harden by evaporation ofthe thinner on exposure to ventilated atmospheres at room temperature;examples of these are shellac, oxidizing alkyds, and cellulose nitratelacquers. Other coatings, such as those based on urea-formaldehyde ormelamine-formaldehyde resins, undergo condensation polymerizationreactions. This usually requires the application of heat.

When temperatures above 150° F. are used to dry a coating, the resultantcomposition is said to be a baked coating. Some coatings, such as thosebased on linseed oil, form dry films by way of polymerization reactionswhich are induced by absorption of atmospheric oxygen, leading to thesubsequent gelation and hardening of the composition. Still others maybe applied at elevated temperatures without a volatile solvent and driedby cooling them to room temperature. An example of this type is thevinyl copolymer coating often calendered into fabrics.

SUMMARY OF THE INVENTION

Applicant has now discovered a novel, fluid-resistant, fire-retardantcoating composition having improved weather resistance and enhancedbonding strength coupled with a high degree of aesthetic appeal. Thesecompositions may be sprayed, brushed or rolled onto the surface ofnumerous diverse substrates including, but not limited to, glass orglass fibers, fiberboard, wood, stone, cement, styrofoam, etc. to form afire retardant and water resistant flexible coating having a highbonding strength and good chipping and peeling resistance.

One embodiment of the present invention comprises a coating compositionhaving the following components: a liquid latex polymer suspension, anacrylic emulsion, a gypsum-based powder compound and an adhesivematerial. The mixture may further comprise a drying agent selected fromplaster of Paris and Gesso to chemically combine with the liquidsolvent. The effect of this material is to reduce the drying time of thecoating, thus reducing the interval before a coated substrate may be putinto service or before a second coat of the material may be added.

The latex polymer suspension may further include additional additivessuch as pigments, antifoaming agents and glycerols which may be providedby the addition of a water-based latex paint containing such a latexpolymer suspension. The percentage of solids represented by these latexsuspensions are not critical to the compositions of the invention, andcan vary over a wide range of between 1 and 50 weight percent. Solidscontents below 1 percent provide a composition containing a high amountof water which must be compensated for by adding more acrylic solids,gypsum or adhesive. Solids contents above 50%, on the other hand, causethe formulations to be more difficult to mix and may require thatadditional water be added.

A preferred latex polymer suspension is ordinary housepaint. Within suchwater-based paints, the percentage solids typically ranges between about5-25% by weight and preferably 10-20% by weight. The latex polymersuspension component typically comprises between about 1-2 parts byvolume of applicant's coating composition, although other ranges can beused.

Regarding the acrylic emulsion, this component is soluble in aqueoussolvents and contains a percentage of solids ranging between about 35and 50%, and preferably between 40 and 45%, by weight. As with the latexsuspension, the percent solids of the acrylic emulsion can vary over awide range such as from about 25 to 75 weight percent without departingfrom the invention. The emulsion component preferably constitutesbetween about 3-4 parts of the coating composition, by volume.

The source of the gypsum-based powder component is preferably aspackling or plastering powder which constitutes between about 1-2 partsof the coating composition by volume. The gypsum adds strength anddurability to the coated surface and is particularly effective inabsorbing the aqueous component of the latex polymer suspension. Thiscomponent may be increased when latex and acrylic emulsions having a lowsolids content are used to absorb excess water.

The adhesive material which is used to facilitate the bonding of thecomponents, both to one another and to an underlying substrate, ispreferably a glue. This material represents between about 1-3 parts byvolume of the coating composition and may either be added separately orin combination with the gypsum-based powder composition. Glues for usein applicant's coating composition may be selected from among animal andvegetable glues and synthetic plastic adhesive resins.

In a further embodiment, the composition may also include one or morefiller materials which serve to reinforce the coating, facilitating theproduction of reinforced sheets or laminates which may be cut to arequired size and rolled for storage with a negligible amount ofcracking, chipping or peeling of the coating, in contrast to other knowncoating materials. These filler materials may be selected from amongglass beads, glass fibers, carbon fibers, mineral aggregates, cloths,whether woven or in fiber form and metal powders. In order to form thesereinforced sheets or laminates, applicant's coating composition may beapplied to one or more layers of a substrate formed by the fillermaterials and permitted to cure.

In a still further embodiment of applicant's invention, the coatingcomposition may itself serve as an adhesive to bind two substratestogether. The coating, with or without a reinforcing filler, mayinitially be applied to the surface of a first substrate, such asmasonry, wood, stone, cement or concrete, and, while still in a viscousstate, a second substrate, selected from among styrofoam, cloth or otherwoven materials, fiberboard, steel sheets, wood paneling, wallpaper andthe like, may be pressed against the coated surface of the firstsubstrate to facilitate an adhesion therebetween.

DETAILED DESCRIPTION OF THE INVENTION

The best mode of practicing the present invention specifically relatesto a composition which includes the following ingredients: an aqueouscolloidal latex polymer suspension; an acrylic polymer emulsion; a drygypsum-based powder and a glue. With regard to the latex polymersuspension utilized by applicant, this composition is preferablycomprised of a polymer dispersion of polyvinyl acetate/acrylic resinesters in an aqueous solvent. Such synthetic resin latexes are commonlyencountered constituents of latex adhesives, and thus they also serve toenhance the adhesive capability of applicant's coating material. Inaddition to the latex polymers described above, a number of additivecompositions may also be included with the latex suspension so as toenhance the covering and bonding properties of applicant's coatingcomposition.

For example, one or more varieties of colorizing materials, such astitanium dioxide (TiO₂) and other commonly used organic and inorganicpigments, may be added in order to impart a preferred color to thecoating composition. Such materials may be added in amounts ranging upto 100% by weight of the latex polymer suspension. Antifoaming agents,such as silicate compounds, may also be included These are commonlyutilized by those skilled in the art to prevent the foaming which maylead to the formation of emulsions in the mixing stage. A furtherworthwhile additive is a glycerol compound, e.g., ethylene glycol, whichmay be included with the latex as a "freeze-thaw" additive to preservethe fluidity of the composition despite temperature variations duringits storage and application.

The percentage of solids contained within the latex dispersion is notcritical to the invention and any amount thereof may be used to compounda usable component of applicant's coating composition. In order toproduce an easily workable and mixable composition however, applicanthas found that between about 1-50%, more preferably 5-25%, and mostpreferably between about 10-20% solids by weight is advantageous.

An especially preferred latex polymer suspension may be introduced intoapplicant's coating composition by the addition of a commerciallyavailable latex base paint, such as Regal® Wall Satin Latex InteriorPaint, which is manufactured by Benjamin Moore & Co. of Montvale, N.J.In these paints, the percentage of solids ranges from about 15-20% byweight. It has also been determined that the additives normally includedin paint formulations such as those described above do not detract fromthe properties obtainable by the compositions of the invention, and arepreferred for use therein.

With regard to the acrylic polymer emulsion component of applicant'scoating composition, this material serves as a binder to maintain thepigment particles in a coherent film and to enhance the bonding strengthof the coating to an underlying substrate upon which it is applied. By"acrylic emulsion," applicant means a dispersion of an acrylic polymerin an organic or an aqueous medium. The percentage of solids within thesuspension also is not critical to the invention and any amount may beused. However, to obtain a workable and mixable consistency in theresulting composition, it has been found that between about 25 and 75,preferably 35 and 50, and most preferably between 40 and 45 percentsolids by weight is most advantageous.

An especially preferred acrylic polymer emulsion is Liquitex® AcrylicGloss Medium and Varnish manufactured by Binney and Smith of Easton,Pennsylvania. Other commonly used acrylic polymer emulsions, however,include poly(methyl methacrylate) compositions such as Rhoplex AC 33,manufactured by the Rohm & Haas Company of Philadelphia, Pennsylvaniaand Lucite 44 and 45, manufactured by the DuPont Corporation of DelawareIn the former, the emulsion is water soluble, while in the latter, thecomposition has a pastelike consistency and is only soluble in organicsolvents such as turpentine.

The third ingredient of applicant's coating is a gypsum-basedcomposition such as a plaster powder or a spackling powder. The term"gypsum" as used herein is intended to include gypsum such as isnormally understood in the art. This would include calcium sulfate(CASO₄) and its various forms such as calcium sulfate anhydrate, calciumsulfate hemihydrate, and calcium sulfate dihydrate, as well as calcinedgypsum, pressure calcined gypsum, and plaster of Paris. One purpose ofthe gypsum component is to strengthen the coating composition byincreasing the hardness of the coating surface. In addition, the gypsumcomponent also forms a strong bond between the coating and theunderlying substrate. Furthermore, the coating material acts as anadhesive while drying due to the inclusion of the gypsum component sothat additional construction materials, i.e., panels, cloths, foams,wallpapers, moisture barriers and the like, may be contacted against thesurface of the coating and retained thereupon once the composition iscompletely dry.

A still further reason for the addition of they gypsum component is thatthis material is very hygroscopic and thus serves as an ideal vehicle toabsorb the aqueous solvent which serves as a carrier for the latexdispersion. This solvent absorption is necessary in order to permit thecoating composition to cure into a durable layer which is highlyresistant to peeling, chipping or cracking from the underlyingsubstrate. Compositions of this type which are especially preferred foruse with applicant's coating composition include Durabond PowderSpackling Putty produced by USG Industries, Inc. of Chicago, Ill.

The fourth component of applicant's coating composition is an adhesivematerial, such as a glue. The glue may be added independently, as by theaddition of a product such as Elmers® Glue-All produced by Borden, Inc.of Columbus, Ohio, or, for convenience, it may be added in combinationwith the above-described gypsum component by the addition of a productsuch as Glue Base Plaster Patch, produced by United GilsoniteLaboratories of Scranton, Pa.

By the term "glue", applicant is referring to both natural and syntheticsubstances used for joining or bonding other materials together bysurface attachment. Materials commonly referred to as "glue," "paste,""mucilage," "rubber cement" and the like would therefore be includedwithin this class. The term "glue," as used by applicant, is intended toinclude not only animal, casein and vegetable glues and natural resinsbut also the synthetic plastic resins, which may be incorporated withinapplicant's coating composition to perform a similar bonding function.

The drying time of applicant's coating compositions, which normallyaverages about one-half hour per coat, may be reduced by the addition ofa drying agent. Any material capable of chemically combining with thewater in the composition to reduce the setting, i.e, hardening, time maybe used but the preferred additives are those which include additionalgypsum in the form of, for example, plaster of Paris or Gesso, i.e., amixture of glue, water and gypsum. These inexpensive additives haveproven to be highly efficient in reducing the drying time of the coatingdue to their highly hygroscopic nature and their compatibility with theother components of the coating composition.

Also, when relatively low solids content latex dispersions and/oracrylic emulsions are used, a greater amount of gypsum component can beused. This provides coatings which are harder, more dense, and lessflexible than coating compositions utilizing higher solids content latexdispersions and acrylic emulsions. Conversely, where greater flexibilityof the coating is desired, a greater amount of latex and acrylic solidsand a lesser amount of gypsum component may be used.

In small quantities, the components of the coating may be mixed togetherby hand by stirring the dry powder gypsum-based component into a mixtureof the liquid-based latex dispersion together with the acrylic polymeremulsion. The glue may be introduced as a viscous liquid or, when addedin combination with one of the gypsum-based compositions, it may also bestirred into the mixture as a dry powder. In larger quantities, such asthose required for the commercial manufacture and distribution of thecoating, it is useful to apply mixing techniques and procedures similarto those utilized in the manufacture of paints, varnishes, lacquers andthe like, which are well-known to those skilled in this art.

As noted above, applicant's novel composition may be coated upon avariety of substrates to both improve the aesthetic appeal thereof andto protect their surfaces from damage due to the effects of fire andmoisture. The composition of the invention may further includeadditional pigments, fillers and reinforcing materials where desired forcertain applications. Standard paint additives for imparting a widechoice of colors to the composition are easily introduced, as arewell-known fillers or reinforcements, such as glass beads, glass fibers,carbon fibers, mineral aggregates, cloths, whether woven or in fiberform, metal powders, etc., which impart improved physical properties tothe coating material. If desired, special additives such asantioxidants, U.V. stabilizers, antifoaming agents, etc. can be added tothe composition to impart certain desired features to the coating.

A preferred embodiment of the invention contemplates the formation of acoated product produced by the application of the above-describedcoating composition to a substrate such as a layer of a fibrousmaterial, e.g., glass or ceramic fibers, or woven cloth, matte orfabric, so as to form fiber-reinforced sheets or laminates. Theseproducts comprise a layer of the fiber reinforcement, whether random orwoven, coated with a desired thickness of applicant's coatingcomposition. The resultant fabric-like product may then serve as astructural support and protective layer for various constructionapplications.

An optimum coating thickness for forming such coated sheets ranges fromabout 0.03-0.06 inch but other thicknesses may be used depending uponthe particular requirements of the intended application. The materialmay, for example, be cast into sheets or laminates for application tovertical or horizontal wall surfaces in order to both beautify theseareas and to protect them from the effects of fire as well as wearproduced by the elements. These coated sheets or laminates may be rolledand stored prior to their installation with minimal danger of cracking,chipping or peeling of the reinforced coating material in comparison tocoating materials lacking such reinforcement. If desired, however, thisreinforced coating composition may be sprayed or brushed onto suchsurfaces in areas where the application of sheets or laminates is notpractical or desired.

In addition, applicant's coating composition may be applied directly tothe surface of substrates such as masonry, wood, fiberboard, styrofoam,stone, cement, concrete and the like by spraying, brushing, trowelingetc. to provide a fast bonding, weather-resistant protective coatingthereupon. These coated substrates are then very useful in theproduction of both interior and exterior structural components and theymay subsequently be painted or wallpapered to enhance their aestheticappeal. In addition, when the coating composition is applied directlyonto the surface of a substrate, it can also serve as an adhesive tojoin styrofoam, fiberboard, steel or wood paneling, wallpaper, etc. tosubstrates such as structural components comprised of masonry, cement,stone, wood, concrete, etc. Applicant's composition thus provides astrong, inexpensive bond between these materials without the use offastening means such as nails, screws or bolts. However, applicant'sreinforced products can be attached to a substrate by adhesives or bysuch fastening means, if desired.

EXAMPLES

The following examples disclose the preferred composition of applicant'scoating and demonstrate the strength and durability of these coatings bysetting forth the results of various comparative tests. These examplesare set forth for the purposes of illustration only and are not to beconstrued as limiting the invention in any manner.

EXAMPLE 1

A coating composition as taught by applicant was produced by combiningthe following components:

    ______________________________________                                                           Parts (by volume)                                          ______________________________________                                        liquid acrylic emulsion                                                                            3-4                                                      latex polymer suspension                                                                           1-2                                                      gypsum-based composition                                                                           1-2                                                      glue                 1-3                                                      ______________________________________                                    

A minimal amount of water (less than 1 part by volume) was also added tothe composition as necessary to assist in the hydration of thegypsum-based material Upon mixing, the composition formed afluid-resistant, fire-retardant coating composition which resistsshipping and cracking from a substrate to which it is applied.

EXAMPLE 2

An especially preferred coating composition was produced according tothe present invention by combining:

    ______________________________________                                                           Parts (by volume)                                          ______________________________________                                        Liquitex ® Acrylic Gloss                                                                       3.5                                                      Medium and Varnish                                                            Regal ® Wall Satin Latex                                                                       1.5                                                      Interior Flat Paint                                                           Durabond Spackling Powder                                                                          1.5                                                      Glue Base Plaster Patch                                                                            2                                                        ______________________________________                                    

This composition, when mixed and placed within an airtight container hasmaintained its liquid consistency for an extended period and remainscapable of forming a durable coating upon an interior or exteriorstructural surface.

EXAMPLE 3

The composition of Example 2 was coated upon a piece of plywood to athickness of about 0.04 inch. The coated wood was then permitted toremain outdoors, exposed to the elements, for over one year with nodetectable change in the color of the coating and with no deteriorationof the underlying wood substrate. This clearly supports applicant'scontention that the coating composition of the invention serves not onlyto enhance the aesthetic appearance of the coated substrate but also toprotect the surface of the substrate from the effects of the elements.

EXAMPLE 4

In flame spread tests wherein applicant's novel composition was coatedonto a woodfiber board and compared with ceiling tiles coated with astandard coating composition manufactured by Armstrong World Industries,Inc., of Lancaster, Pa., the time required to spread a test flame acrossthe surface of the woodfiber board coated by the composition of theinvention was inhibited by up to 14% compared to standard fire-retardantcoated ceiling tile. Whereas the flame required only 53 seconds tospread across the surface of the comparison ceiling panel, 61 secondswere required for the panel coated with applicant's composition tobecome engulfed. This is clearly indicative of the fire-resistantproperties of applicant's novel coating.

While it is apparant that the invention herein disclosed is wellcalculated to fulfill the desired results, it will be appreciated thatnumerous modifications and embodiments may be devised by those skilledin the art, and it is intended that the appended claims cover all suchmodifications and embodiments as fall within the true spirit and scopeof the present invention.

I claim:
 1. A flexible coated product which comprises:(1) a coatingcomposition comprising(a) from about 1-2 parts by volume of a liquidlatex polymer suspension of a blend of polyvinyl acetate/acrylic resinesters dispersed in an aqueous solvent to impart an increased level offlexibility to said composition; (b) from about 3-4 parts by volume ofan acrylic emulsion to serve as a film-forming binder for saidcomposition; (c) from about 1-2 parts by volume of a powderedgypsum-based compound to impart a required degree of strength anddurability to said coating composition and to absorb substantially amajor portion of said aqueous solvent which comprises said liquid latexpolymer suspension; and (d) from about 1-3 parts by volume of a glue tobond together said polymer suspension, said acrylic emulsion and saidpowdered, gypsum-based compound and to faciliate adhesion of saidcoating composition to a substrate to which said coating composition isto be applied; and (2) a reinforcing material,wherein said coatingcomposition is applied to said substrate to form a flexible coatedproduct.
 2. The coated product of claim 1 wherein said reinforcingmaterial comprises a fibrous material
 3. The coated product of claim 2wherein said fibrous material is a plurality of randomly oriented glassfibers.
 4. The coated product of claim 2 wherein said fibrous materialcomprises a woven or nonwoven cloth, mesh or fabric.
 5. The coatedproduct of claim 1 wherein said substrate is in the form of a flat layerso that the product forms a sheet or laminate.
 6. The coated product ofclaim 1 further comprising a filler material.
 7. The coated product ofclaim 6 wherein the filler material is glass beads, glass fiber, carbonfiber, mineral aggregate, cloth, metal powder or mixtures thereof. 8.The coated product of claim 1 wherein said coating composition isapplied directly to the surface of a substrate to facilitate theadhesion of said reinforcing material thereto.
 9. The coated product ofclaim 7 wherein said substrate is selected from the group consisting ofmasonry, wood, stone, cement and concrete.
 10. A coated productcomprising a first substrate, the composition of claim 1 and a secondsubstrate, wherein said composition is located between at least aportion of said fist and said second substrates to adhesively bind saidsubstrates together.
 11. The coated product of claim 10 wherein saidcoating composition is applied directly to the surface of said firstsubstrate to facilitate the adhesion of said second substrate thereto.12. The coated product of claim 10 wherein said second substrate isselected from the group consisting of styrofoam, fiberboard, steelsheets, wood panelling, wallpaper, glass fibers or cloth.
 13. The coatedproduct of claim 1 wherein said liquid latex polymer suspension furtherincludes one or more additives selected from the group consisting ofpigments, antifoaming agents and glycerols.
 14. The coated product ofclaim 13 wherein said liquid latex polymer suspension is a water-basedlatex paint.
 15. The coated product of claim 1 wherein said liquid latexpolymer suspension comprises between about 5-25% solids by weight. 16.The coated product of claim 1 wherein said acrylic emulsion is solublein an aqueous medium and wherein said emulsion comprises between about35-50% solids by weight.
 17. The coated product of claim 1 wherein saidpowdered, gypsum-based compound is a gypsum-based spackling orplastering powder.
 18. The coated product of claim 1 wherein said glueis selected from the group consisting of animal glues, vegetable gluesand synthetic adhesive plastic resins.
 19. A flexible coated productwhich comprises:(1) a coating composition comprising(a) from about 1-2parts by volume of a water-based latex paint comprising a polymerdispersion of a blend of polyvinyl acetate/acrylic resin esters; (b)from about 3-4 parts by volume of a liquid acrylic emulsion; (c) fromabout 1-2 parts by volume of a powdered, gypsum-based material; and (d)from about 1-3 parts by volume of a glue-based adhesive material, and(2) a substrate to provide a support for said coating composition. 20.The coated product of claim 19 wherein said coating composition furthercomprises a reinforcing material.
 21. The coated product of claim 19wherein said coating composition further comprises a filler material.